Noble metal alloys are important in large-scale catalytic processes. Alloying facilitates fine-tuning of catalytic properties via synergistic interactions between metals. It also allows for dilution of scarce and expensive metals using comparatively earth-abundant metals. RhAg and RhAu are classically considered to be immiscible metals. We show here that stable RhM (M = Ag, Au) nanoparticles with randomly alloyed structures and broadly tunable Rh:M ratios can be prepared using a microwave-assisted method. The alloyed nanostructures with optimized Rh:M compositions are significantly more active as hydrogenation catalysts than Rh itself: Rh is more dilute and more reactive when alloyed with Ag or Au, even though the latter are both catalytically inactive for hydrogenation. Theoretical modeling predicts that the observed catalytic enhancement is due to few-atom surface ensemble effects in which the overall reaction energy profile for alkene hydrogenation is optimized due to Rh-M d-band intermixing.

Six new precursors for lead sulfide nanoparticles were synthesized by the reaction of lead acetate, with picolinic (Hpic), 2,6-dipicolinic (H 2 dipic) or salicylic (H 2 sal) acid followed by the addition of thiourea (tu) or thiosemicarbazide (ths). The compounds are "[Pb(Hsal) 2 (tu) 2 ]" (1a), "Pb(Hsal) 2 -(ths, and 3b formed well-defined crystals and were characterized by single-crystal X-ray diffraction, while the remaining compounds were characterized spectroscopically and by elemental analyses. The precursors were decomposed in both aqueous and nonaqueous media leading to pure crystalline galena in all cases. Depending upon conditions truncated octahedra, dendrites, nanocubes, interlinked nanocubes, nanohexapods and cubes were obtained. To elucidate the effect of single-source precursors on the mechanism of growth of nanoparticles, we compared the decomposition results with PbS nanostructures synthesized from multiple-source precursors using lead acetate with thiourea or thiosemicarbazide.

The chemistry of metastable RhPd alloys is not well understood, and well‐characterized nanoparticle (NP) examples remain rare. Well‐defined and near‐monodisperse RhPd NPs were prepared in a simple one‐pot approach by using microwave‐assisted or conventional heating in reaction times as short as 30 s. The catalytic hydrogenation activity of supported RhPd NP catalysts revealed that short synthesis times resulted in the most‐active and most‐stable hydrogenation catalysts, whereas longer synthesis times promoted partial Rh‐Pd core–shell segregation. Relative to Rh NPs, RhPd NPs resisted deactivation over longer reaction times. Density functional theory (DFT) was employed to estimate the binding energies of H and alkenes on (1 1 1) Rh, Pd, and Rh0.5Pd0.5 surfaces. The DFT results concurred with experiment and concluded that the alkene hydrogenation activity trend was of the order Pd

High quality crystalline Co-CUK-1 can be synthesized rapidly and efficiently by a microwave-assisted method. The resulting microporous coordination material is a highly effective adsorbent for the separation of xylene isomers and ethylbenzene, as demonstrated here through sorption isotherm analysis, Ideal Adsorbed Solution Theory (IAST) calculations, and grand canonical Monte Carlo (GCMC) simulations. Co-CUK-1 showed high sorption capacity and high adsorption selectivity for p-xylene over the corresponding m- and o-isomers, and ethylbenzenes. According to the data obtained from IAST and GCMC simulations, the Co-CUK-1 is found to strongly favour p-xylene adsorption because p-xylene molecules undergo well-defined molecular packing in the 1-D channels; by comparison, the packing efficiencies of o-xylene, m-xylene and ethylbenzene are significantly lower, as is evidenced by lower saturation capacities.